Semiconductor light emitting device

ABSTRACT

A semiconductor light emitting device comprises an element that emits light and a substrate on a main surface of which the element is mounted. The main surface of the substrate composed of two areas, (i) a mount area which is rectangle and on which the element is mounted, and (ii) a pad area that is equipped with a pad for wire bonding. The pad area is contiguous to the mount area on one side of the mount area, and the pad area decreases in width continuously or stepwise in a direction away from the one side.

TECHNICAL FIELD

The present invention relates to a semiconductor light emitting devicein which a flip chip semiconductor light emitting element is mounted ona submount substrate, and particularly to a technique for setting asemiconductor light emitting device in a smaller space than theconventional ones.

BACKGROUND ART

In recent years, with an improvement of a technique of semiconductors,semiconductor light emitting devices that output white light to beequipped in lighting apparatuses have become widely used.

Especially, semiconductor light emitting devices are compact and requirelow electric power. Therefore, semiconductor light emitting devices aresuitable for installing in portable devices such as cellular-phones andcameras, and should explosively prevail in the near future.

A semiconductor light emitting device comprises: a semiconductor lightemitting element that emits blue light; and translucent resinscatteredly including luminescent substance that converts blue lightinto greenish yellow light, greenish yellow being a complementary colorof blue. The semiconductor light emitting device outputs light thatlooks white by outputting (a) a part of blue light that is emitted by asemiconductor light emitting element and transmits translucent resinwithout being converted by the luminescent substance, and (b) greenishyellow light that is generated as a result of conversion by theluminescent substance, at the same time in a proper proportion.

The details about the aforementioned semiconductor light emitting deviceare disclosed in Japanese Patent Publication No. 3257455 and No. 3399440filled by the applicants of the present invention.

The aforementioned semiconductor light emitting device comprises asubmount substrate and a flip chip semiconductor light emitting elementthat is mounted on the submount substrate, and needs a space for wirebonding on the submount substrate. Therefore, the submount substrateneeds to be larger than the semiconductor light emitting element, andthe semiconductor light emitting element is mounted on the submountsubstrate in an unbalanced position where a center of the semiconductorlight emitting element does not coincide with a center of the submountsubstrate. It should be noted here that generally a main surface of thesemiconductor light emitting element is substantially square and a mainsurface of the submount substrate is substantially rectangular.

Also, it is preferable that the semiconductor light emitting device isequipped with a cup-like reflection member to reflect the light emittedin parallel with a main light emitting surface by the semiconductorlight emitting element so that the light travels in a directionperpendicular to a main light emitting surface.

The reflection member is a metal plate that has aconical-trapezoidal-shaped hole, as one example. On a bottom of thereflection member, the semiconductor light emitting element is provided.Radius of the reflection member decreases from a top toward a bottom.

Also a lens made of transparent resin or the like is provided over thereflection member to improve light distribution characteristic, and itis preferable to keep a radius on a bottom as small as possible takingthe amount of materials and light focusing efficiency into account.

However, taking a light distribution characteristic into consideration,if a center of main light emitting surface of the semiconductor lightemitting element is adjusted to coincide with a center of the reflectionmember, a space for wire bonding sticks out from the main light emittingsurface. This would make a radius on a bottom of the reflection memberconsiderably larger than a shape of the submount substrate. Nonetheless,adjusting a center of the submount substrate to coincide with a centerof the reflection member should be avoided because it causes adegradation of light distribution characteristic. Also, reducing a spacefor wire bonding should be avoided because it increases bonding defects,lowers a yield ratio, and diminishes productivity due to an effort toimprove accuracy.

The aim of the present invention is to provide a semiconductor lightemitting device that can be set in a smaller space than the conventionalones without sacrificing light distribution characteristic andproductivity and to provide a method for manufacturing the semiconductorlight emitting device.

DISCLOSURE OF THE INVENTION

The semiconductor light emitting device of the present inventioncomprises an element to emit light and a substrate on a main surface ofwhich the element is mounted. The main surface of the substrate composedof two areas, (i) a mount area which is rectangular and on which theelement is mounted, and (ii) a pad area that is equipped with a pad forwire bonding. Here, the pad area is contiguous to the mount area on oneside of the mount area, and the pad area decreases in width continuouslyor stepwise in a direction away from the one side.

With this structure, a width of the pad area decreases with the distancefrom the element. This enables to keep a space for wire bonding withoutbeing inferior to the prior art, and to decrease a radius of a bottom ofa cup-like reflection member with attention to light distributioncharacteristic by adjusting a center of a main light emitting surface ofthe element to coincide with a center of the reflection member.Therefore, it is possible to reduce the amount of materials and toimprove light focusing efficiency.

Also, this structure has only two areas, the mount area and the padarea, on the main surface of the substrate. In other words, there is nowasted space on the substrate. This allows greater flexibility to cutoff substrates from an array substrate such as a silicon wafer and toincrease the number of substrates that can be cut off from an arraysubstrate, compared with circular or polygonal substrates (a hexagonsubstrate, for one example) on which an element needs to be mounted in amiddle.

Consequently, according to the present invention, it is possible to seta semiconductor light emitting element in a smaller space than theconventional ones without sacrificing light distribution characteristicand productivity.

A shape of the pad area of the semiconductor light emitting device canbe an isosceles trapezoid whose long base coincides with the one side.

With this arrangement, since the pad area is an isosceles trapezoid, itis possible to make the pad area easily just by cutting off diagonallytwo corners of the conventional rectangle pad area.

Also, a shape of the pad area of the semiconductor light emitting devicecan be an isosceles triangle whose base coincides with the one side.

With this arrangement, since the pad area is an isosceles triangle, itis possible to make the pad area easily just by cutting off diagonallytwo corners of the conventional rectangle pad area.

Also, a shape of the pad area of the semiconductor light emitting devicecan be a circular arc whose chord coincides with the one side.

With this arrangement, since the pad area is a circular arc, it ispossible to set the semiconductor light emitting device along a form ofa reflection member, and to keep a space for wire bonding. Therefore, itis possible to further reduce a radius on a bottom of a reflectionmember.

Also, a shape of the pad area of the semiconductor light emitting devicecan be a half regular polygon obtained by dividing a regular polygon bya symmetrical line, and a longest side of the half regular polygoncoincides with the one side.

With this arrangement, since the pad area is a half regular polygon, itis possible to make the pad area just by cutting off as many sides ofthe pad area as needed. The larger the number of sides of the polygonis, the larger a space for wire bonding is. Thus, it is possible tofurther reduce a radius of a bottom of a reflection member where thesemiconductor light emitting device is provided.

Further, the semiconductor light emitting device may comprises aphosphor to change a wavelength of the light emitted by the element. Theelement can be mounted substantially in the center of the mount area,and the mount area can be covered entirely together with the element, bythe phosphor.

With this arrangement, since the mount area is covered entirely by thephosphor, it is possible to cut the phosphor in a horizontal directionalong with three sides of the substrate when cutting off substrates froman array substrate by dicing. Therefore, it is possible to diminishdeviation in thicknesses of the phosphor without increasing amanufacturing process, and to diminish deviation in colors and partialdiscoloration.

Also, in the semiconductor light emitting device, an electrode that isincluded in the element and is connected to the pad can be positionedsubstantially in the center of one of two sides of the mount area thatis connected to the one side.

With this arrangement, in the pattern where the substrates are arrangedto face respectively right and left to increase the number of substratesthat can be cut off from an array substrate, it is possible to bond theelements while they face the same direction when bonding the elements onan array substrate by die bonding. Therefore, a mechanism to turnelements needs not to be equipped in a die bonding machine.

Also the semiconductor light emitting device may further comprises acup-like reflection member to reflect the light that is emitted inparallel with the main surface by the element so that the light travelsin a direction perpendicular to the main surface, and a center of a mainlight emitting surface of the element coincides with a center of thereflection member.

With this arrangement, the reflection member enables to reflect thelight emitted in parallel with a main light emitting surface by theelement so that the light travels in a direction perpendicular to themain surface. Therefore, it is possible to improve luminous efficiency.Further, light distribution characteristic is improved and luminousunevenness can be diminished by adjusting a center of a main lightemitting surface of the element to coincide with a center of thereflection member.

Also, the semiconductor light emitting device may further comprise alens to output the light emitted by the element toward an object. Here,a center of the main light emitting surface of the element coincideswith an optical center of the lens.

With this arrangement, the lens enables to output the light emitted bythe element toward an object. Therefore, it is possible to improve lightdistribution characteristic and light directional characteristic.Further, a light distribution characteristic is improved and luminousunevenness can be diminished by adjusting a center of a main lightemitting surface of the element to coincide with an optical center ofthe lens.

The method for manufacturing the semiconductor light emitting device ofthe present invention comprises (a) an array substrate generating stepfor generating an array substrate of substrates arranged in a uniquearrangement pattern, (b) a die bonding step for bonding elementsrespectively on the substrates arranged in the array substrate by diebonding, and (c) a cutting step for cutting the array substrate intoindividual semiconductor light emitting devices by dicing. Here, in thearrangement pattern mentioned above, a side of the mount area that isopposite to the one side is adjoined by a side of another mount area foranother element, with two elements on the mount area and said theanother mount area adjoining back to back.

With this arrangement, it is possible to increase the number ofsubstrates that can be cut off from an array substrate.

The method for manufacturing the semiconductor light emitting device mayfurther include an applying step, between the die bonding step and thedicing step, for applying the phosphor to the elements in a uniqueapplication pattern. Here, in the application pattern, the phosphor isapplied collectively to the two elements that are adjoining back to backcentering on the adjoining sides.

With this arrangement, it is possible to apply the phosphor collectivelyto the elements adjoined back to back. Therefore, manufacturingefficiency is improved.

Also, the phosphor can be cut off at the same time when cutting offsubstrates from an array substrate by dicing. Therefore, it is possibleto diminish deviation in thicknesses of the phosphor without increasinga manufacturing process.

Also, in the die bonding step of the method for manufacturing thesemiconductor light emitting device, an electrode that is included inthe element and is connected to the pad can be positioned substantiallyin the center of one of two sides of the mount area that is connected tothe one side, and such that all of the elements face the same direction.

With this arrangement, it is possible to bond the elements while theyface the same direction when bonding the elements on the array substrateby die bonding. Therefore, a mechanism to turn elements needs not to beequipped in a die bonding machine.

The method for manufacturing the semiconductor light emitting device ofthe present invention may includes (a) an array substrate generatingstep for generating an array substrate of substrates arranged in aunique arrangement pattern, (b) a mount step for mounting the elementsrespectively on the substrates in the array substrate, and (c) a cuttingstep for cutting the array substrate into individual semiconductor lightemitting devices by dicing. Here, in the arrangement pattern, (i) evennumber rows in which substrates that each have a mount area on the leftand a pad area on the right are connected with each other in aleft-right direction and (ii) odd number rows in which substrates thateach have a mount area on the right and a pad area on the left areconnected with each other in left-right direction, may be alignedalternately.

With this arrangement, it is possible to increase the number ofsubstrates that can be cut off from an array substrate.

The method for manufacturing the semiconductor light emitting device mayfurther include an applying step, between the die bonding step and thecutting step, for applying the phosphor to the elements in a uniqueapplication pattern. Here, in the arrangement pattern, there are marginsbetween two elements adjoining in rows, and in the application pattern,deviation of an application width is controlled by the margins.

With this arrangement, it is possible to improve productivity becausethe margins enable to control deviation of an application width.

Also, in the die bonding step of the method for manufacturing thesemiconductor light emitting device, an electrode that is included inthe element and is connected to the pad can be positioned substantiallyin the center of one of two sides that is connected to the one side, andsuch that all of the semiconductor light emitting elements face the samedirection.

With this arrangement, it is possible to bond the elements while theyface the same direction when bonding the elements on substrates by diebonding, therefore, a mechanism to turn elements needs not to beequipped in a die bonding machine.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows an appearance of a lighting device 10 that comprises anumber of light emitting modules respectively including semiconductorlight emitting devices of the first embodiment.

FIGS. 2A and 2B show details of the light emitting module 20 of FIG. 1.FIG. 2 shows the light emitting module 20 without a lens viewed at apoint where the light is received therefrom. FIG. 2B is a crosssectional view of the light emitting module 20 taken along the lineA-A′.

FIG. 3A shows an appearance of the semiconductor light emitting device100 described in the first embodiment.

FIG. 3B shows the semiconductor light emitting device 100 of FIG. 3Aviewed at a point where the light is received therefrom.

FIG. 3C is a front view of the semiconductor light emitting device 100of FIG. 3B.

FIG. 4 is a schematic diagram showing a method for manufacturing thesemiconductor light emitting device 100 of the first embodiment.

FIG. 5 shows one example of the arrangement patterns unique to thepresent invention.

FIG. 6 shows one example of the sheets of the submount substrates 130 onwhich all of the semiconductor light emitting elements 110 are connectedby bump connecting.

FIG. 7 shows one example of the sheets of the submount substrates 130 onwhich a phosphor is applied/printed in a unique application pattern.

FIG. 8A and FIG. 8B show semiconductor light emitting devices whose padareas are trapezoids viewed at a point where the light is receivedtherefrom. In a semiconductor light emitting device 300 shown in FIG.8A, the mount area has an extended long side. In a semiconductor lightemitting device 310 shown in FIG. 8B, the mount area has anot-remarkably-extended long side.

FIG. 9A and FIG. 9B show semiconductor light emitting devices whose padareas are triangles viewed at a point where the light is receivedtherefrom. In a semiconductor light emitting device 320 shown in FIG.9A, the mount area has an extended long side. In a semiconductor lightemitting device 330 shown in FIG. 9B, the mount area has anot-remarkably-extended long side.

FIG. 10A and FIG. 10B show light emitting devices whose pad areas arecircular arcs viewed at a point where the light is received therefrom.In a semiconductor light emitting device 340 shown in FIG. 10A, themount area has an extended long side. In a semiconductor light emittingdevice 350 shown in FIG. 10B, the mount area has anot-remarkably-extended long side.

FIG. 11A and FIG. 11B show semiconductor light emitting devices whosepad areas are half regular polygons (Octagon is used in the drawing)viewed at a point where the light is received therefrom. In asemiconductor light emitting device 360 shown in FIG. 10A, the mountarea has an extended long side. In a semiconductor light emitting device370 shown in FIG. 10B, the mount area has a not-remarkably-extended longside.

FIG. 12 shows one example of the arrangement patterns unique to thepresent invention.

FIG. 13 is one example of the sheets of the submount substrates on whichall of the semiconductor light emitting elements are connected by bumpconnecting.

FIG. 14 shows one example of the sheets of submount substrates 130 whenthe phosphor is applied/printed in an application pattern unique to thepresent invention.

FIG. 15 shows other example of the arrangement patterns unique to thepresent invention.

FIG. 16 is other example of the sheets of submount substrates 130 onwhich all of the semiconductor light emitting elements are connected bybump connecting.

FIG. 17 shows other example of the sheets of the submount substrates 130when the phosphors are applied/printed in an application pattern uniqueto the present invention.

FIG. 18 is other example of the arrangement patterns unique to thepresent invention.

FIG. 19 is other example of the sheets of submount substrates on whichall of semiconductor light emitting elements 110 are connected by bumpconnecting.

FIG. 20 shows other example of the sheets of submount substrates 130when the phosphors are applied/printed in an application pattern uniqueto the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment <GeneralDescription>

The inventors of the present application focused attention on a pointthat corners of a space for wire bonding on conventional rectangularsubstrates do not function efficiently as a pad for wire bonding, inspite that the corners are one of the factors that affect a minimum sizeof cup-like reflection members and lenses. This embodiment provides asemiconductor light emitting device in which corners of a space for wirebonding are improved in shape. The semiconductor light emitting deviceof the present invention can be set in a smaller space than conventionalones without sacrificing light distribution characteristic andproductivity. Also, the semiconductor light emitting device of thepresent invention enables to reduce the amount of materials and toimprove light focusing efficiency.

<Structure>

FIG. 1 shows an appearance of a lighting device 10 that comprises anumber of light emitting modules respectively including semiconductorlight emitting devices of the first embodiment.

As shown in FIG. 1, the lighting device 10 of the first embodiment is alight emitting panel that outputs white light to be used forilluminations, and comprises eight terminals 11 to receive an electricsupply and sixty-four light emitting modules 20 that are arranged in aneight-by-eight matrix. The lighting device 10 outputs white light byconnecting the outer terminals 11 to a power source and making each ofthe light emitting module 20 emit light.

FIGS. 2A and 2B show details of the light emitting module 20 of FIG. 1.FIG. 2 shows the light emitting module 20 without a lens viewed at apoint where the light is received therefrom. FIG. 2B is a crosssectional view of the light emitting module 20 taken along the lineA-A′.

As shown in FIG. 2A and FIG. 2B, the light emitting module 20 comprisesa device substrate 21, a wiring pattern 22, a bonding wire 23, areflecting unit 24, a lens unit 25, and a semiconductor light emittingdevice 100. Here, the semiconductor light emitting device 100 isindicated by a shaded part.

The device substrate 21 is a board made of aluminum-based alloy, forexample. It is preferable that the device substrate 21 is made of amaterial that is able to maintain a rigidity of the lighting device 10,and has a high heat conductance to efficiently discharge heat generatedby the semiconductor light emitting device 100.

The wiring pattern 22 is metal foil such as copper foil formed on a mainsurface of the device substrate 21. The wiring pattern 22 includes (a) afirst electrode 26 that is positioned at least in a part on which thesemiconductor light emitting device 100 is to be bonded by die bondingand is electrically connected to one of the outer terminals 11 and (b) asecond electrode 27 that is positioned at least in a part where thebonding wire 23 is to be bonded by wire bonding and is electricallyconnected to another one of the outer terminals 11. It should be notedhere that the first electrode 26 and the second electrode 27 arearranged to be slightly widened to reflect upward the light that comesdownward.

The bonding wire 23 is an electric conductor made of, for example, goldor aluminum, and connects a bonding pad on the semiconductor lightemitting device 100 and the second electrode 27.

The reflecting unit 24 is made by boring holes that are circular in across section in a metal plate made of, for example, aluminum. The holesare bored to fit each of the light emitting module 20, and radii of theholes increase as the distance from a bottom where the semiconductorlight emitting element is provided increases. The reflecting unit 24also can be made by providing conical-trapezoidal cup-like reflectionmembers on a metal plate, radii of reflection members decreasing towarda bottom. The reflection members are provided to fit each of the lightemitting module 20. The reflecting unit 24 is equipped to reflect thelight that is emitted in parallel with a main light emitting surface bythe semiconductor light emitting device 100 so that the light travels ina direction perpendicular to the main light emitting surface. Also, byadjusting a center of a main light emitting surface of the semiconductorlight emitting device 100 to coincide with a center of the reflectingunit 24, light distribution characteristic is improved and luminousunevenness is diminished.

The lens unit 25 is made of resin such as epoxy resin and is formedaccording to a transfer forming method. The lens unit 25 is used tooutput light emitted by the semiconductor light emitting device 100toward an object. It is preferable to restrict the use of filler toimprove light transmission of epoxy resin. Therefore, highly-purifiedepoxy resin with no filler is used for the lens unit 25. Also, byadjusting a center of a main light emitting surface of the semiconductorlight emitting device 100 to coincide with an optical center of the lensunit 25, light distribution characteristic is improved and luminousunevenness is diminished.

FIG. 3A shows an appearance of the semiconductor light emitting device100 described in the first embodiment.

FIG. 3B shows the semiconductor light emitting device 100 of FIG. 3Aviewed at a point where the light is received therefrom.

FIG. 3C is a front view of the semiconductor light emitting device 100of FIG. 3B.

As shown in FIG. 3A, FIG. 3B, and FIG. 3C, the semiconductor lightemitting device 100 is a device to output white light, and comprises asemiconductor light emitting element 110, a translucent resin 120, and asubmount substrate 130.

The semiconductor light emitting element 110 is an element to emit lightwhose main surface is rectangular, such as a light emitting diode thatcomprises a substrate having an optical transparency on which a GaNchemical compound semiconductor layer is formed and emits blue light.The semiconductor light emitting element 110 comprises a sapphiresubstrate 111 that has translucency, a semiconductor layer 112comprising an n type light emitting layer and a p type light emittinglayer, a p electrode 113 that is connected to the p type light emittinglayer, and an n electrode 114 that is connected to the n type lightemitting layer. The semiconductor light emitting element 110 has the pelectrode 113 and the n electrode 114 on the main surface facing thesubmount substrate 130, and the other main surface is a main lightemitting surface that chiefly emits light. Here, the semiconductor lightemitting element 110 is a rectangular parallelepiped whose main surfacebeing 3 mm square and thickness being 0.1 mm, and is mounted on thesubmount substrate 130 as shown in FIG. 3.

The translucent resin 120 scatteredly includes luminescent substance(not shown in drawings) that converts blue light into greenish yellowlight, greenish yellow being a complementary color of blue. Thetranslucent resin 120 is a translucent phosphor made of a resin materialthat transmits (a) blue light which has not been converted to greenishyellow light by the luminescent substance and (b) greenish yellow lightwhich has been generated as a result of conversion by the luminescentsubstance. The translucent resin 120 is mounted on the submountsubstance 130 as shown in FIG. 3 to cover the submount substrate 130 andits surrounding area.

The submount substrate 130 includes a silicon substrate 140 that is aprotective diode such as a zener diode made of basically silicon. Thesubmount substrate 130 is a substrate on which the semiconductor lightemitting element 110 and the translucent resin 120 are mounted, and hasa first counter electrode 131, a second counter electrode 132, and bumpelectrodes 133 and 134 on a mount surface that is a main surface of thesilicon substrate 140 and has the semiconductor light emitting element110 and the translucent resin 120 thereon. Also, a back-side electrode135 is provided on a main surface of the silicon substrate 140 oppositeto the mount surface.

The silicon substrate 140 comprises, (a) an n type semiconductor area141 adjoining the first counter electrode 131 and (b) a p typesemiconductor area 142 adjoining the second counter electrode 132. Also,at least the counter electrode 132 is provided on a part of the mountsurface that is not covered by the translucent resin 120, and this partis to be a bonding pad 136 to be used for wire bonding.

The following explains a shape of the main surface of the submountsubstrate 130. The main surface of the submount substrate 130 isslightly larger than a main surface of the semiconductor light emittingelement 110, and composed of two areas, (i) a mount area which is arectangle and on which the semiconductor light emitting element 110 andthe translucent resin 120 are mounted and (ii) a pad area that isequipped with the bonding pad 136. Here, the pad area is contiguous tothe mount area on one side of the mount area, and the pad area decreasesin width continuously or stepwise in a direction from the one side.

Here, the main surface of the submount substrate 130 comprises arectangular mount area whose short sides being 0.4 mm and long sidesbeing 0.42 mm, and an isosceles trapezoidal pad area whose long basebeing 0.4 mm, short base being 0.12 mm, and a height being 0.14 mm. Theshort side of the mount area is contiguous to the long base of the padarea, and a thickness is 0.2 mm. It should be noted here that the longbase of the pad area denotes a longer side of parallel sides of anisosceles trapezoid.

Also, various diodes such as a zener diode, a pn diode, a pin diode, ashottky barrier diode, a tunnel diode, and a gun diode can be used asthe silicon substrate 140.

Here, the silicon substrate 140 that is a protective diode is connectedwith the semiconductor light emitting element 110 that is a lightemitting diode, by electrodes that have reversed polarities. With suchan arrangement in which a protective diode is connected with a lightemitting diode, even if an attempt is made to apply a reverse voltage tothe light emitting diode, a reverse voltage is hardly applied to thelight emitting diode because electric current flows forward to theprotective diode. Also, even if an attempt is made to apply an excessiveforward voltage to the light emitting diode, a higher voltage than areverse breakdown voltage (a zener voltage) of the protective diode isnot applied. In a case where a silicon diode is used as the protectivediode, usually a forward voltage can be set at approximately 0.9 V, areverse breakdown voltage at approximately 10 V. On the other hand, aforward breakdown voltage of a GaN light emitting diode is approximately100V, and a reverse breakdown voltage is approximately 30V. Therefore,it is possible to assuredly prevent a light emitting diode from beingdestroyed by an excessive voltage due to static electricity and such.

A light emitting diode that emits blue light is mainly GaN-based, andhas less resistance to static electricity compared with other bulkchemical compound semiconductors GaP-based or GaAlAs-based. Therefore,the arrangement in which various diodes are used in the submountsubstrate 130 produces great effect. However, the submount substrate 130may not necessarily be composed of diodes in cases where other measuresare taken against static electricity or where a semiconductor lightemitting element such as other bulk chemical compound semiconductorsthat has high resistance to static electricity is used.

The first counter electrode 131 is electrically connected to the pelectrode 113 equipped on the semiconductor light emitting element 110,by the bump electrode 133, and the second counter electrode 132 iselectrically connected to the n electrode 114 equipped on thesemiconductor light emitting element 110, by the bump electrode 134.When a voltage is applied between the first counter electrode 131 andthe second counter electrode 132, the light emitting element 110 emitslight.

It should be noted here that the light emitting element 110 is notlimited to an element that emits blue light. An element that emitsultraviolet light can be the light emitting element 110 as an example.In this case, a translucent resin 120 includes luminescent substancethat excites the ultraviolet light emitted by the semiconductor lightemitting element 110 to emit blue light, red light and green light, andis a translucent phosphor comprising resin material that transmits theblue light, the red light, and the green light which is generated by theluminescent substance.

<Method for Manufacture>

FIG. 4 is a schematic diagram showing a method for manufacturing thesemiconductor light emitting device 100 of the first embodiment.

The following describes a method for manufacturing the semiconductorlight emitting device 100 with reference to FIG. 4.

(1) A sheet of the submount substrates 130 (an array substrate) ismanufactured by manufacturing a wafer of the silicon substrate 140 whichis a zener diode made of basically silicon and by equipping the waferwith the first counter electrodes 131, the second counter electrodes 132and the back-side electrode 135 (Step S1). Here, the present methoddiffers from the conventional method in that it uses a uniquearrangement pattern.

FIG. 5 shows one example of the arrangement patterns unique to thepresent invention.

In FIG. 5, the submount substrates 130 are indicated by shaded parts,and each broken line indicates positions to be cut by dicing. Whencutting off a shaded part 200 at the upper left, for example, it ispreferable to cut it along the broken lines in the ascending order ofthe reference numbers, from 201 to 206, because chipping can beprevented by cutting longer side first.

(2) A wafer of the semiconductor light emitting elements 110 ismanufactured and attached onto a dicing tape. Then after being dividedinto chips by dicing, the wafer is expanded together with the dicingtape so that each chip of the semiconductor light emitting element 110can be picked up easily (Step S2).

(3) The sheet of the submount substrates 130 is put in place on a XYtable for bump connecting based on the shape and an alignment mark onthe sheet (Step S3).

(4) The dicing tape on which the semiconductor light emitting elements110 are attached is put in a place on a XY table for picking upsubstrates (Step 4).

(5) Bump electrodes 133 and 134 are generated at each position on thesubmount substrates 130 where the semiconductor light emitting element110 is to be connected by bump connecting (Step S5).

(6) The semiconductor light emitting elements 110 are picked up one byone from the dicing tape by moving the XY table for bump connecting. Ona midway stage, accuracies of directions and positions are improved, andthe semiconductor light emitting elements 110 are connected to each ofthe submount substrate 130 by bump connecting (Step S6).

(7) After the semiconductor light emitting elements 110 are respectivelyconnected to all of the submount substrates 130 on the sheet, the sheetis transferred to a phosphor printer employing a metal plate (Step 7).

FIG. 6 shows one example of a sheet of the submount substrates 130 onwhich all of the semiconductor light emitting elements 110 are connectedby bump connecting.

In FIG. 6, the semiconductor light emitting elements 110 are indicatedby shaded parts, and each of the broken line indicates positions to becut by dicing.

(8) In the phosphor printing press, a phosphor is applied/printed on thesemiconductor light emitting elements 110 and their surroundings in aunique application pattern (Step S8).

FIG. 7 shows one example of the sheets of the submount substrates 130 onwhich the phosphor is applied/printed in a unique application pattern.

In FIG. 7, the phosphors applied/printed on the sheet are indicated byshaded parts, and broken lines indicate positions to be cut by dicing.

(9) The semiconductor light emitting device 100 is completed after thesheet is divided into each submount substrate 130 by dicing (Step 9).

Here, when the submount substrates 130 are cut off from the sheet bydicing, margins between elements that are adjacent in the row and columndirections are cut off along three sides of the phosphor. Therefore,with an application pattern unique to the present invention, it is easyto control deviation of an application width. For example, in FIG. 7, atranslucent resin 120 at the upper left is formed by cutting along threesides of the phosphor that are shown by broken lines 201, 202, and 203.

<Summary>

As described above, according to the semiconductor light emitting deviceof the first embodiment, corners of a wire bonding area of therectangular submount substrates are improved in shape, and it ispossible to reduce the minimum size of reflection members and lenses.

Consequently, it is possible to set in a smaller space, to reduce theamount of materials, and to improve light focusing efficiency withoutsacrificing light distribution characteristic and productivity ascompared with conventional light emitting devices.

Modification Example 1

The modification example 1 of the present invention shows a modificationof a shape of the pad area described in the first embodiment.

The shape of the pad area is not limited to isosceles trapezoidaldescribed in the first embodiment. The pad area can be other trapezoids,isosceles triangles, other triangles, circular arcs, and half regularpolygons.

FIG. 8A and FIG. 8B show semiconductor light emitting devices whose padareas are trapezoids viewed at a point where the light is receivedtherefrom. In a semiconductor light emitting device 300 shown in FIG.8A, the mount area has an extended long side. In a semiconductor lightemitting device 310 shown in FIG. 8B, the mount area has anot-remarkably-extended long side.

In the semiconductor light emitting devices 300 and 310, the long baseof the isosceles trapezoid coincides with a short side of the mountarea.

FIG. 9A and FIG. 9B show semiconductor light emitting devices whose padareas are triangles viewed at a point where the light is receivedtherefrom. In a semiconductor light emitting device 320 shown in FIG.9A, the mount area has an extended long side. In a semiconductor lightemitting device 330 shown in FIG. 9B, the mount area has anot-remarkably-extended long side.

In the semiconductor light emitting devices 320 and 330, a base of theisosceles triangle coincides with a short side of the mount area.

FIG. 10A and FIG. 10B show light emitting devices whose pad areas arecircular arcs viewed at a point where the light is received therefrom.In a semiconductor light emitting device 340 shown in FIG. 10A, themount area has an extended long side. In a semiconductor light emittingdevice 350 shown in FIG. 10B, the mount area has anot-remarkably-extended long side.

In the semiconductor light emitting devices 340 and 350, a chord of thecircular arc coincides with a short side of the mount area.

FIG. 11A and FIG. 11B show semiconductor light emitting devices whosepad areas are half regular polygons (Octagon is used in the drawing)viewed at a point where the light is received therefrom. In asemiconductor light emitting device 360 shown in FIG. 10A, the mountarea has an extended long side. In a semiconductor light emitting device370 shown in FIG. 10B, the mount area has a not-remarkably-extended longside.

In the semiconductor light emitting devices 360 and 370 shown in FIG.11A and FIG. 11B, a longest side of the half regular polygon coincideswith a short side of the mount area.

Here, in the semiconductor light emitting devices 300, 320, 340 and 360,long sides of mount areas are extended. Therefore, it is easy toapply/print a translucent resin.

In the semiconductor light emitting devices 300 and 310, it is possibleto have a large space between a wire and the submount substrate.Therefore, credibility is high. Also, the semiconductor light emittingdevices 300 and 310 can be simply made just by cutting off diagonallytwo corners of the conventional rectangular pad area.

In the semiconductor light emitting devices 320 and 330, it is possibleto reduce a radius of a bottom of the reflection member. Therefore,reflection efficiency is improved. The semiconductor light emittingdevices 320 and 330 can be simply made just by cutting off diagonallytwo corners of the conventional rectangular mount area. Further, thesemiconductor light emitting device 330 has a large wire bonding areaand exhibits high bond quality.

The semiconductor light emitting devices 340 and 350 can be setsubstantially along a form of the reflection member. Also it is possibleto keep a space for wire bonding and to reduce radius of a bottom of areflection member where the semiconductor light emitting device isprovided.

Further, the semiconductor light emitting devices 360 and 370 can bemade just by cutting off as many sides of the pad areas as needed, andthe larger the number of sides of the polygons are, the larger spacesfor wire bonding are. Thus, it is possible to further reduce a radius ofa bottom of a reflection member where the semiconductor light emittingdevice is provided.

Modification Example 2

The modification example 2 shows one example of arrangement patternsunique to the present invention in a case where the pad area is atriangle.

FIG. 12 shows one example of arrangement patterns unique to the presentinvention.

In FIG. 12, shaded parts indicate the submount substrates whose padareas are triangles, and each broken line indicates positions to be cutby dicing. When cutting off a shaded part 400 at the upper left, forexample, it is preferable to cut it along the broken lines in theascending order of the reference numbers, from 401 to 405, becausechipping can be prevented by cutting the longer sides first.

Also, in FIG. 12, it is possible to make the pad area trapezoidal bycutting along the broken line 406 with a thick blade.

FIG. 13 is one example of the sheets of the submount substrates on whichall of the semiconductor light emitting elements are connected by bumpconnecting.

In FIG. 13, the semiconductor light emitting elements are indicated byshaded parts, and each broken line indicates positions to be cut bydicing.

Here, as shown in FIG. 13, the semiconductor light emitting elements 110are mounted on the submount substrates 130 such that the n electrode 114that is included in a semiconductor light emitting element 110 and isconnected to the pad is positioned substantially in the center of a sideof the mount area that is connected to the one side, and such that allof the semiconductor light emitting elements 110 face the samedirection.

As described above, by making all of the semiconductor light emittingelements 110 face the same direction, it is possible to bond thesemiconductor light emitting elements while they face the samedirection, when bonding the semiconductor light emitting elements on thesheet by die bonding. Therefore, a mechanism to turn elements needs notto be equipped in a die bonding machine.

FIG. 14 shows one example of the sheets of submount substrates 130 whenthe phosphor is applied/printed in an application pattern unique to thepresent invention.

In FIG. 14, the phosphors that are applied/printed on the submountsubstrates 130 are indicated by shaded parts, and each broken lineindicates positions to be cut by dicing.

As shown in FIG. 12, with the unique arrangement pattern, a side of themount area that is opposite to the one side is adjoined by a side ofanother mount area for another element, with two elements on the mountarea and another mount area adjoining back to back, and it is possibleto increase the number of substrates that can be cut off from the arraysubstrate. Also, as shown in FIG. 14, when applying/printing thephosphors, the phosphors can be applied/printed collectively to twoelements that are adjoining back to back centering on the adjoiningsides. Further, it is possible to apply/print the phosphors onto linestogether in a vertical direction.

Modification Example 3

The modification example 3 shows other example of the arrangementpatterns unique to the present invention described in the firstembodiment in a case where the pad area is a triangle.

FIG. 15 shows other example of the arrangement patterns unique to thepresent invention.

In the FIG. 15, shaded parts indicate the submount substrates whose padareas are triangles, and each broken line indicates positions to be cutby dicing. Here, when cutting off a shaded part 410 at the upper left,for example, it is preferable to cut it along the broken lines in theascending order of the reference numbers, from 411 to 415, becausechipping can be prevented by cutting the longer sides first.

Also, in FIG. 15, it is possible to make the pad area trapezoidal bycutting along the broken line 416 with a thick blade.

FIG. 16 is other example of the sheets of submount substrates 130 onwhich all of the semiconductor light emitting elements are connected bybump connecting.

In FIG. 16, the semiconductor light emitting elements 110 are indicatedby shaded parts, and each broken line indicates positions to be cut bydicing.

Here, as same as the modification example 2, the semiconductor lightemitting elements 110 are mounted on the submount substrates 130 suchthat the n electrode 114 that is included in the semiconductor lightemitting element 110 and is connected to the pad is positionedsubstantially in the center of a side of the mount area that isconnected to the one side, and such that all of the semiconductor lightemitting elements 110 face the same direction.

As described above, by making all of the semiconductor light emittingelements face the same direction, it is possible to bond thesemiconductor light emitting elements while they face the same directionwhen bonding the semiconductor light emitting elements on the sheet bydie bonding. Therefore, a mechanism to turn elements needs not to beequipped in a die bonding machine.

FIG. 17 shows other example of the sheets of the submount substrates 130when the phosphors are applied/printed in an application pattern uniqueto the present invention.

In FIG. 17, phosphors that are applied/printed on the submountsubstrates 130 are indicated by shaded parts, and each broken lineindicates positions to be cut by dicing.

As shown in FIG. 15, with the unique arrangement pattern, a side of themount area that is opposite to the one side is adjoined by a side ofanother mount area for another element, with two elements on the mountarea and the another mount area adjoining back to back, and it ispossible to increase the number of substrates that can be cut off fromthe array substrate. Also, when applying/printing the phosphors on theelements, the phosphors can be applied/printed collectively to the twoelements that are adjoining back to back centering on the adjoiningsides. However, this arrangement pattern is arranged to increase thenumber of substrates that can be cut off from the array substrate, andit is not possible to apply/print collectively in the longitudinaldirection as compared with the arrangement pattern of the modificationexample 2. Therefore, as shown in FIG. 17, the phosphors areapplied/printed to be conical trapezoidal forms.

Modification Example 4

The modification example 4 shows other example of arrangement patternsunique to the present invention described in the first embodiment in acase where the pad area is a triangle.

FIG. 18 is other example of the arrangement patterns unique to thepresent invention.

In the FIG. 18, shaded parts indicate submount substrates whose padareas are triangles, and each broken line indicates positions to be cutby dicing. Here, when cutting off a shaded part 420 at the upper left,for example, it is preferable to cut it along the broken lines in theascending order of the reference number, from 421 to 425, becausechipping can be prevented by cutting the longer side first.

FIG. 19 is other example of the sheets of submount substrates on whichall of semiconductor light emitting elements 110 are connected by bumpconnecting.

In FIG. 19, the semiconductor light emitting elements 110 are indicatedby shaded parts, and each broken line indicates positions to be cut bydicing.

Here, as same as the modification example 2, the semiconductor lightemitting elements 110 are mounted on the submount substrates 130 so thatthen electrode 114 that is included in the semiconductor light emittingelement 110 and is connected to the pad is positioned substantially inthe center of a side of the mount area that is connected to the oneside, and such that all of the semiconductor light emitting elements 110face the same direction.

As described above, by making all of the semiconductor light emittingelements 110 face same direction, it is possible to bond thesemiconductor light emitting elements while they face the same directionwhen bonding semiconductor light emitting elements on the sheet by diebonding. Therefore, a mechanism to turn elements needs not to beequipped in a die bonding machine.

FIG. 20 shows other example of the sheets of submount substrates 130when the phosphors are applied/printed in an application pattern uniqueto the present invention.

In FIG. 20, the phosphors that are applied/printed on the submountsubstrates 130 are indicated by shaded parts, and each broken lineindicates positions to be cut by dicing.

As shown in FIG. 20, in the modification example 4, it is possible toincrease the number of substrates that can be cut off from the arraysubstrate. Also, the array substrate of the submount substrates 130 hasmargins. Therefore, it is possible to control deviation of anapplication width and to improve productivity.

It should be noted here that means to cut off the submount substratesfrom the array substrate is not limited to the dicing technique. Anytechnique such as lasers and sandblastings can be used to cut off thesubmount substrates. For example, a laser enables to cut in any form.Therefore, a laser can be applied in any case including cases wheremaking the pad area circular arcs or half regular polygons.

INDUSTRIAL APPLICABILITY

The semiconductor light emitting device of the present invention is ableto apply to any lighting equipment and display. Especially, it ispossible to provide compact and lightweight light sources. Therefore,the semiconductor light emitting device of the present invention has agreat deal of potential to install in portable devices such ascellular-phones andc ameras.

1-9. (canceled)
 10. A method for manufacturing a plurality ofsemiconductor light emitting devices, each of the semiconductor lightemitting devices including an element that emits light; and a substrateon a main surface of which the element is mounted, wherein the mainsurface has (i) a mount area which is a rectangle and on which theelement is mounted, and has (ii) a pad area that has a pad for wirebonding, wherein the pad area is contiguous to the mount area on oneside of the mount area, and the pad area decreases in width continuouslyor stepwise in a direction away from the one side, said methodcomprising: an array substrate generating step for generating an arraysubstrate in which substrates are arranged in a unique arrangementpattern; a die bonding step for bonding elements respectively on thesubstrates arranged in the array substrate, by die bonding; and acutting step for cutting the array substrate into individualsemiconductor light emitting devices by dicing, wherein in thearrangement pattern, a side of the mount area that is opposite to theone side is adjoined by a side of another mount area for anotherelement, with two elements on the mount area and said another mount areaadjoining back to back.
 11. The method of claim 10 further including: anapplying step, between the die bonding step and the cutting step, forapplying the phosphor to the elements in a unique application pattern,wherein in the application pattern, the phosphor is applied collectivelyto the two elements that are adjoining back to back centering on theadjoining sides.
 12. The method of claim 10, wherein in the die bondingstep, an electrode that is included in the element and is connected tothe pad is positioned substantially in a center of one of two sides ofthe mount area that are connected to the one side, and such that all ofthe elements face the same direction.
 13. A method for manufacturing aplurality of semiconductor light emitting devices, each of thesemiconductor light emitting devices including an element that emitslight; and a substrate on a main surface of which the element ismounted, wherein the main surface has (i) a mount area which is arectangle and on which the element is mounted, and has (ii) a pad areathat has a pad for wire bonding, wherein the pad area is contiguous tothe mount area on one side of the mount area, and the pad area decreasesin width continuously or stepwise in a direction away from the one side,said method comprising: an array substrate generating step forgenerating an array substrate in which substrates are arranged in aunique arrangement pattern; a mount step for mounting elementsrespectively on the substrates arranged in the array substrate; and acutting step for cutting the array substrate into individualsemiconductor light emitting devices by dicing, wherein in thearrangement pattern, (i) even number rows in which substrates that eachhave a mount area on the left and a pad area on the right are connectedwith each other in a left-right direction and (ii) odd number rows inwhich substrates that each have a mount area on the right and a pad areaon the left are connected with each other in a left-right direction, arealigned alternately.
 14. The method of claim 13 further includes: anapplying step, between the die bonding step and the cutting step, forapplying the phosphor to the elements in a unique application pattern,wherein in the arrangement pattern, there are margins between twoelements in each pair adjoining in a row direction, and in theapplication pattern, deviation of an application width is controlled bythe margins.
 15. The method of claim 13, wherein in the die bondingstep, an electrode that is included in the element and is connected tothe pad is positioned substantially in a center of one of two sides ofthe mount area that are connected to the one side, and such that all ofthe elements face the same direction.